On 7 June 2012, the Department of Homeland security drew up a proposal to purchase 7k select-fire rifles in a 5.56x45mm caliber. In that proposal, the rifles are described as follows:

"DHS and its components have a requirement for a 5.56x45mm NATO, select-fire firearm suitable for personal defense use in close quarters and/or when maximum concealment is required." (Section C(PDW)ver 7.pdf - available in the below link)

Suitable for personal defense in close quarters or maximum concealment, eh? Sounds like a kind of situation one might encounter in their own home and faced with an intruder.

It seems as if in the eyes of the government these are select-fire personal defense tools in the hands of one of their agents. In the hands of a good law abiding citizens they are semi-automatic assault rifle mass killing machines.